Recurrent superficial bladder cancer is a major public health problem. This disease, once recurrences have begun, tends to recur repeatedly, in some case progressing to infiltrating cancer, metastatic disease, and death. The only treatment of established utility is cystoscopy every 3-4 months with fulguration of al visible lesions. Preliminary results that we, and others, have obtained, suggest that intravesical BCG treatment, after fulguration, may prevent or delay local recurrences and eliminate tumor cell shedding (measured by cytology). Of particular importance, this result has been seen in patients with flat carcinoma-in-situ, which experience has shown is associated with a uniquely poor prognosis. This application is a proposal to expand on these results, initially carrying our two new clinical trials. First, patients with papilloma (or grade I carcinoma) will be randomized to fulguration alone or fulguration plus intravesical BCG. Second, patients with Stage O or A cancer will be randomized to intravesical BCG treatment, with or without montly maintenance courses. Antitumor effects in the treatment groups will be compared using standard, objective measurements, such as, number of tumors per patient-month of follow-up, disease-free interval, change in urinary cytology, etc. In addition, flow cytometry of the urinary cellular content after acridine orange staining will be investigated as a new way to quantify tumor cell shedding.